Table 1.

Physiological parameters of isolated EDL muscles used in ex vivo force measurements

	WT	mdx	DysΔMTB-mdx	Sgcb-/-	P value
EDL mass (mg)	12.8  ± 0.4a	18.1   ± 0.7b	11.7  ± 0.2c	22.7  ± 0.4b,c,d	P < 0.001
L0 (mm)	13.3  ± 0.2a	13.1  ± 0.2	12.2  ± 0.2b,c	13.6  ± 0.1d	P = 0.003
CSA (cm2)	0.021  ± 0.001a	0.030  ± 0.001b	0.021  ± 0.001c	0.036  ± 0.001b,c,d	P < 0.001
Passive stiffness (N/m)	13.9  ± 0.9a	19.9  ± 0.8b	13.1  ± 1.3c	16.2  ± 1.2b,c,d	P < 0.001
P0 (mN)	449  ± 8.8a	415  ± 12.8	424  ± 21.3	347  ± 25.0b,c,d	P < 0.001
Specific P0 (N/cm2)	21.8  ± 0.5a	14.1  ± 0.3b	20.6  ± 0.9c	9.7  ± 0.6b,c,d	P < 0.001
ΔP0 (%)	11.1  ± 3.1a	86.7  ± 2.6b	11.0  ± 5.1c	80.9  ± 2.5b,d	P < 0.001
Force drop (%)	9.4  ± 5.7a	87.1  ± 1.3b	8.5  ± 2.3c	62.3  ± 3.0b,c,d	P < 0.001

Values are means ± SE.

L₀ = optimal muscle length, CSA = physiological cross sectional area, P₀ = maximal isometric tetanic force. ΔP₀ = change in P₀ after eccentric contractions. Force drop =change in eccentric force from the first to the fifth eccentric contraction. n ≥ 4 for each line. Statistics were performed using two-way ANOVA with post-hoc t-test analyses with P < 0.05 considered significant.

^aWT data were previously reported and shown here for comparison (9)

^bSignificantly different than WT.

^cSignificantly different than mdx.

^dSignificantly different than Dys^ΔMTB-mdx.